Weaning and Allergy Preven/on Dr Carina Venter Senior Allergy Die//an The David Hide Asthma and Allergy Research Centre University of Portsmouth University of Southampton
There is much to learn about preventing food allergy De Silva et al. 2014
Objec/ves Weaning recommenda/ons Do we follow these recommenda/ons? Importance of first tastes as later determinants of later food preference Weaning /ming/type of foods and NCDs
The recommenda/ons Cardiovascular, metabolic, chronic lung diseases and allergic diseases are all collec/vely known as non- communicable diseases (NCDs). We have seen an increase in all of these NCDs over the past few decades. Early life nutri/on play a significant role in the future preven/on or development of non- communicable diseases (NCDs). PrescoQ et al. 2013
Infant feeding Weaning (introduc/on of solid foods) age and ideal dura/on of exclusive breast feeding go hand in hand Exclusive breasweeding, based on the WHO defini/on, refers to: The prac/ce of feeding only breast milk (including expressed breast milk) and allows the baby to receive vitamins, minerals or medicine. Water, breast milk subs/tutes, other liquids and solid foods are excluded. hqp://www.who.int/nutri/on/topics/infanweeding/en/
WHO recommenda/on 2001 Exclusive breast feeding for 6 months (i.e. no introduc*on of solid foods) vs. 4-6 months Reduc/on of gastro- intes/nal infec/ons (Belarus) No (further) reduc/on in respiratory infec/ons or atopic disease http://www.who.int/nutrition/publications/optimal_duration_of_exc_bfeeding_report_eng.pdf
Introduc/on of solid foods Na/onal Guidelines Country Introduction of solids Allergy Advice USA (ADA 2009/AAP Committee on Nutrition 2008) UK (DoH/BDA) EAACI 2014 (De Silva et al. 2014) Australia (NHMRC2003 and DAA) ADA: Complementary foods from 6 months AAPCN: after 4 months of age, preferably at 6 months of age DoH 2007: Weaning should commence around or about 6 months of age. Delaying the introduction of solid foods beyond 4 months did not have preventive benefits in those at high or normal risk. NHMRC 2003: Should not be started before the age of 4 months and that they should not be delayed much beyond the age of 6 months. DAA: 6 months ADA None AAPCN This includes highly allergenic foods, such as fish, eggs, and foods containing peanut protein. DoH: If weaning commenced before 6 months: avoid wheat-based foods, eggs, fish, shellfish, nuts, seeds and soft and unpasteurised cheeses. Therefore, for primary prevention we recommend no withholding or encouraging of exposure to highly allergenic foods such as cow s milk, hen s egg and peanuts irrespective of atopic heredity, once weaning has commenced. NHMRC: Avoid nuts until 3 years if there is a strong family history of nut allergy. DAA: None
Do we follow these guidelines?
USA Country Solid foods introduced Introduction of nuts USA (1993/1994) Skinner et al. 1997 (n=98) Most infants by six months By 12 months 6/60 (10%) ate nuts the day before USA (2005) IFPS II n~ 3000 USA (2013) IFS II n=1334 83.9% fed cereal foods by 6 months 41% by 4 months 40.4% of mothers introduced solid foods before age 4 months 7% giving nuts by 10 months hqp://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/@dh/@en/documents/digitalasset/dh_4059763.pdf
UK Country Solid foods introduced Introduction of nuts UK IFS (2000) n~9 000 IOW (2001) n = 969 UK IFS (2005) n~12 000 85% at 4 months 82.1% by 4 months all children by 6 months 51% at 4 months 98% by 6 months Not available 20% of children with fam hx of atopy avoiding peanuts at 3 years 1% giving nuts by 10 months IFS (2010) n~16 000 30% by 4 months In England only: 29% exclusively breasted at 6-8 weeks 13% par/ally breaswed at 6-8 weeks DNSIYC 2011-2013 (2700) 78% (ever breast fed) Only 43% breast fed /ll 3 months hqp://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/@dh/@en/documents/digitalasset/dh_4059763.pdf
Australia Updated na/onal allergy guidelines are associated with reduced delay in introduc/on of solids, egg, and peanut and an increase in par/ally hydrolyzed formula use among formula- fed infants. Higher socioeconomic status and absence of family history of allergies were associated with beqer uptake of feeding guidelines. Tey D 2014
Importance of first tastes and later determinants of food preferences
When are babies ready to be weaned? Loss of the neonatal gag reflex An ability to propulse food from entry point to the back of the tongue Able to mas/cate more textured foods - at a later stage? Each infant is different Koplin and Allen 2013
Variety of tastes Taste (sweet, sour, salty, biqer, umami, or savory) preferences have a strong innate component. Sweet, umami, and salty substances are innately preferred BiQer and sour substances are innately rejected This can be modified by pre- and postnatal experiences - learning beginning in utero and con/nue during early feedings. This set the stage for later food choices and are important in establishing life- long food habits. Beauchamp and Menalla 2009
Importance of introducing new tastes BreasWeeding and variety early in weaning increased new food acceptance. Frequency of change during weaning was more effec/ve than number of vegetables fed. The combina/on of breasweeding and high variety produced greatest new food intake. This effect persisted 2 months later. Maier AS 2008
Age of introduc/on - ALSPAC Age solids introduced Feeding difficulties at 15 months <6 months 29.1% 6-9 months 38.6% >10 months 52.3% Harris G 2012
The importance of textures ALSPAC Infants introduced to lumps late ( 10 months of age) were more difficult to feed and had more definite food likes and dislikes. Children who were introduced to lumpy solids arer 9 months of age ate fewer of all ten categories of fruit and vegetables than children introduced to lumpy solids before this age Children introduced to lumpy solids before the age of six months ate more green vegetables, tomatoes and citrus fruits than children introduced arer 6 months. Northstone K, 2001and Harris, G 2008
General weaning guidance not to forget Infants who are weaned at or near 6 months will need to be moved from smooth pureed foods onto the second stage of weaning more quickly. In particular mashed food with soft lumps and soft finger foods and foods high in iron including meat, oily fish and pulses should be introduced from around 6 months.
Oral motor skills: seen die//an vs. not Miriam Tarkin unpublished
Weaning and allergy
Modified from Prof Susan PrescoQ AAAAI 2011/2012 Epigenetics and Genetics Topical exposure Tryptophan Microbiota Vitamin A Konieczna et al. 2012
Healthy ea/ng and solid foods Predominantly home cooked Low/negative intake of highly processed adult foods Low use of commercial baby foods LESS FOOD ALLERGY Grimshaw K JACI 2013
Food diversity? n= 3142 Finnish children By 3 and 4 months of age, food diversity was not associated with any of the allergic end points. By 6 months of age, less food diversity was associated with increased risk of allergic rhini/s but not with the other end points. By 12 months of age, less food diversity was associated with increased risk of any asthma, atopic asthma, wheeze, and allergic rhini/s. Nwaru et al. 2014
Age BreasWeeding dura/on the overlap Breast/formula Milk Solid food
Introduc/on of solids Infants who were diagnosed with food allergy by the /me they were 2 years of age were introduced to solids earlier ( 16 weeks of age) and were less likely to be receiving breast milk when cow's milk protein was first introduced into their diet. Grimshaw et al. 2013
Prof Susan Prescott AAAAI 2011
Timing of exposure? Du Toit and Katz 2008 LEAP and EAT!!!! Too early? Increased risk window Tolerance induction Too late? Increased risk Resolution Birth 3-4? 6-7? Katz 2008 Factors that influence the capacity for tolerance: Gut barriers Micro flora T-cells B-cells Breast feeding (continued) Genetic predisposition Allergen properties (dose, interval, timing, preparation) Other Immunological factors (stress/fatty acids/anti-oxidants) >12 months LEAP and EAT???? Adapted from Prescott SL 2008
Observational data: Cow s milk Prospec)ve study of feeding history of 13,019 infants: IgE- CMA occurrence as a func)on of the age of CMP introduc)on. q Group I (Green): CMP exposure (0 to 14 days) q Group II (Yellow): CMP exposure (15 to 104 days) q Group III (Red): CMP exposure (105 to 194 days) q Group IV (Yellow): CMP exposure (195 to 374 days) Real need for RCT s in this area: LEAP and EAT studies in the UK
Observational data: Egg
RCT: Egg Introducing egg powder into infant s diet at 4-8 months. A high proportion (31% [15/49]) of infants randomized to receive egg had an allergic reaction to the egg powder and did not continue powder ingestion. At 4 months of age, before any known egg ingestion, 36% (24/67) of infants already had egg-specific IgE levels of greater than 0.35 kilounits of antibody (kua)/l. At 12 months, a lower (but not significant) proportion of infants in the egg group (33%) were given a diagnosis of IgEmediated egg allergy compared with the control group. Palmer et al. JACI 2013
and so we have been wai/ng for this! Early evidence, which requires further inves/ga/on, suggests that if a window of opportunity for promo/ng tolerance exists, it may be different for each food. Koplin and Allen, 2013
Changes in foods included: seen a die//an vs. not Following the dietetic consultation, the Number of allergenic foods included in the infant s diet increased significantly (p=0.001) BSACI poster presenta)on Tarkin M et al. 2013
AAP 2008 All infants There is also liqle evidence that delaying the /ming of the introduc/on of complementary foods beyond 4 to 6 months of age prevents the occurrence of atopic disease. At present, there are insufficient data to document a protec/ve effect of any dietary interven/on beyond 4 to 6 months of age for the development of atopic disease. Although solid foods should not be introduced before 4 to 6 months of age, there is no current convincing evidence that delaying their introduc/on beyond this period has a significant protec/ve effect on the development of atopic disease regardless of whether infants are fed cow milk protein formula or human milk. This includes highly allergenic foods, such as fish, eggs, and foods containing peanut protein. Greer 2008
AAAAI 2013 Introduce foods from between 4-6 months Single ingredients one every 3-5 days US: rice or oat cereal, yellow/orange vegetables, fruits (eg, apples, pears, and bananas), green vegetables, and then age- appropriate staged foods with meats. Acid fruits rashes
AAAAI allergenic foods We do not suggest introducing one of the highly allergenic foods as one of the first complementary foods; however, once a few typical complementary foods (see above bullet) are tolerated, highly allergenic foods may be introduced as complementary foods. Fleischer et al. 2013 Therefore, for primary prevention we recommend no withholding or encouraging of exposure to highly allergenic foods such as cow s milk, hen s egg and peanuts irrespective of atopic heredity, once weaning has commenced. EAACI 2014
A final word about weaning...from Dr Sicherer in 2008! At present, it seems reasonable to recommend weaning between the age of 4 6 months, based on the needs of the mother and infant. In practical terms, weaning of high risk infants will involve to begin solids with single ingredient infant foods such as fruits, vegetables, and cereal grains, gradually and in progression, which typically results in the more allergenic foods not being introduced immediately at 4 months, and only if there have not been signs of atopic disease. Scott Sicherer 2008
Special considera/ons Infant with moderate- to- severe atopic derma//s despite op/mized management If specific IgE to a food is posi/ve and not has not been eaten = food challenge Convincing history and SPT/Specific IgE not suppor/ve Sibling with peanut allergy Fleischer et al. 2013
Finally Do introduce solids but limited informa/on When? Which order? How much? Should we follow strict 6 months guidance
Key references Greer FR, Sicherer SH, Burks AW; American Academy of Pediatrics CommiQee on Nutri/on; American Academy of Pediatrics Sec/on on Allergy and Immunolog Effects of early nutri/onal interven/ons on the development of atopic disease in infants and children: the role of maternal dietary restric/on, breasweeding, /ming of introduc/on of complementary foods, and hydrolyzed formulas. Pediatrics. 2008 Jan;121(1):183-91. doi: 10.1542/peds.2007-3022. de Silva D, Geromi M, Halken S, Host A, Panesar SS, Muraro A, Werfel T, Hoffmann- Sommergruber K, Roberts G, Cardona V, Dubois AE, Poulsen LK, Van Ree R, Vlieg- Boerstra B, Agache I, Grimshaw K, O'Mahony L, Venter C, Arshad SH, Sheikh A Primary preven/on of food allergy in children and adults: systema/c review. Allergy. 2014 Jan 16. doi: 10.1111/all.12334 Fleischer DM, Spergel JM, Assa'ad AH, Pongracic JA. Primary preven)on of allergic disease through nutri)onal interven)ons. J Allergy Clin Immunol Pract. 2013 Jan;1(1):29-36. doi: 10.1016/j.jaip. 2012.09.003. Epub 2012 Nov 22.